package com.holofeed.core;

import java.util.ArrayList;

import android.app.ActionBar;
import android.app.ActionBar.Tab;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentTransaction;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.os.Bundle;
import android.support.v13.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;

import com.facebook.android.DialogError;
import com.facebook.android.Facebook;
import com.facebook.android.Facebook.DialogListener;
import com.facebook.android.FacebookError;
import com.holofeed.R;

public class HoloMainActivity extends Activity {

	public static Facebook facebook = new Facebook("173646142755403");
	private Editor editor;
	private ViewPager mViewPager;
	private TabsAdapter mTabsAdapter;
	private SharedPreferences mPrefs;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);

		SharedPreferences settings =
				getSharedPreferences("holofeed_prefs", Activity.MODE_PRIVATE);
		editor = settings.edit();

		mViewPager = new ViewPager(this);
		mViewPager.setId(R.id.pager);
		setContentView(mViewPager);

		final ActionBar bar = getActionBar();
		bar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
		bar.setDisplayShowTitleEnabled(false);

		mTabsAdapter = new TabsAdapter(this, mViewPager);
		mTabsAdapter.addTab(bar.newTab().setText("Simple"), FeedFragment.class,
				null);
		mTabsAdapter.addTab(bar.newTab().setText("List"),
				FriendsFragment.class, null);

		mPrefs = getPreferences(MODE_PRIVATE);
		editor = mPrefs.edit();

		String access_token = mPrefs.getString("access_token", null);
		long expires = mPrefs.getLong("access_expires", 0);
		if (access_token != null) {
			facebook.setAccessToken(access_token);
		}
		if (expires != 0) {
			facebook.setAccessExpires(expires);
		}

		/*
		 * Only call authorize if the access_token has expired.
		 */
		if (!facebook.isSessionValid()) {

			facebook.authorize(this, new String[] {}, new DialogListener() {
				@Override
				public void onComplete(Bundle values) {
					editor.putString("access_token", facebook.getAccessToken());
					editor.putLong("access_expires",
							facebook.getAccessExpires());
					editor.commit();
				}

				@Override
				public void onFacebookError(FacebookError error) {
				}

				@Override
				public void onError(DialogError e) {
				}

				@Override
				public void onCancel() {
				}
			});
		}
	}

	@Override
	public void onActivityResult(int requestCode, int resultCode, Intent data) {
		super.onActivityResult(requestCode, resultCode, data);

		facebook.authorizeCallback(requestCode, resultCode, data);
	}

	/**
	 * This is a helper class that implements the management of tabs and all
	 * details of connecting a ViewPager with associated TabHost.  It relies on a
	 * trick.  Normally a tab host has a simple API for supplying a View or
	 * Intent that each tab will show.  This is not sufficient for switching
	 * between pages.  So instead we make the content part of the tab host
	 * 0dp high (it is not shown) and the TabsAdapter supplies its own dummy
	 * view to show as the tab content.  It listens to changes in tabs, and takes
	 * care of switch to the correct paged in the ViewPager whenever the selected
	 * tab changes.
	 */
	public static class TabsAdapter extends FragmentPagerAdapter implements
			ActionBar.TabListener, ViewPager.OnPageChangeListener {
		private final Context mContext;
		private final ActionBar mActionBar;
		private final ViewPager mViewPager;
		private final ArrayList<TabInfo> mTabs = new ArrayList<TabInfo>();

		static final class TabInfo {
			private final Class<?> clss;
			private final Bundle args;

			TabInfo(Class<?> _class, Bundle _args) {
				clss = _class;
				args = _args;
			}
		}

		public TabsAdapter(Activity activity, ViewPager pager) {
			super(activity.getFragmentManager());
			mContext = activity;
			mActionBar = activity.getActionBar();
			mViewPager = pager;
			mViewPager.setAdapter(this);
			mViewPager.setOnPageChangeListener(this);
		}

		public void addTab(ActionBar.Tab tab, Class<?> clss, Bundle args) {
			TabInfo info = new TabInfo(clss, args);
			tab.setTag(info);
			tab.setTabListener(this);
			mTabs.add(info);
			mActionBar.addTab(tab);
			notifyDataSetChanged();
		}

		@Override
		public int getCount() {
			return mTabs.size();
		}

		@Override
		public Fragment getItem(int position) {
			TabInfo info = mTabs.get(position);
			return Fragment.instantiate(mContext, info.clss.getName(),
					info.args);
		}

		@Override
		public void onPageScrolled(int position, float positionOffset,
				int positionOffsetPixels) {
		}

		@Override
		public void onPageSelected(int position) {
			mActionBar.setSelectedNavigationItem(position);
		}

		@Override
		public void onPageScrollStateChanged(int state) {
		}

		@Override
		public void onTabSelected(Tab tab, FragmentTransaction ft) {
			Object tag = tab.getTag();
			for (int i = 0; i < mTabs.size(); i++) {
				if (mTabs.get(i) == tag) {
					mViewPager.setCurrentItem(i);
				}
			}
		}

		@Override
		public void onTabUnselected(Tab tab, FragmentTransaction ft) {
		}

		@Override
		public void onTabReselected(Tab tab, FragmentTransaction ft) {
		}
	}

}
